How to sort firebase users based on date?

Question

I am trying to represent firebase users to a non technical person. He wants the newest users on top. i have this key value pair on every firebase user node called joinDate. i want to pull data out based on that.

Here is the code

ref.on('value', function(snapshot) {
            var i = 1;
            snapshot.forEach(function(childSnapshot) {
            var childData = childSnapshot.val();
            console.log(childData);
            if (childSnapshot) {
                var emailText = childSnapshot.child("userProfile/email").val();
                var joinDateText = childSnapshot.child("joinDate").val();
                var currentPhyxText = childSnapshot.child("userProfile/currentPhyx").val();
                var nameText = childSnapshot.child("userProfile/name").val();
                var lastNameText = childSnapshot.child("userProfile/lastname").val();
                var progressText = childSnapshot.child("userProfile/progress");
                var lastSeenDateText = childSnapshot.child("userProfile/score/lastDate").val();
                var StringifiedProgressText = JSON.stringify(progressText);

                var email = document.createElement("h4");
                var number = document.createElement("h4");
                var joinDate = document.createElement("h6");
                var currentPhyx = document.createElement("h6");
                var name = document.createElement("h6");
                var lastName = document.createElement("h6");
                var lastDate = document.createElement("h6");
                var lowbackData = document.createElement("h6");
                var progress = document.createElement("h6");
                var br = document.createElement("br");

                email.style.display = "inline";               
                number.style.display = "inline";
                lastName.style.display = "inline";
                name.style.display  = "inline";

                joinDate.textContent = "Join Date :  " + joinDateText;        
                currentPhyx.textContent = "Current Phyx : " + currentPhyxText;
                number.textContent = i+") ";
                email.textContent = emailText;
                name.textContent = "Name : " + nameText;
                lastName.textContent = " " + lastNameText;
                lastDate.textContent = "Last Seen Date : " + lastSeenDateText;
                progress.textContent = "Progress : " + StringifiedProgressText;
                progress.textContent = progress.textContent.replace(/{/g, "");
                progress.textContent = progress.textContent.replace(/}/g, "");
                progress.textContent = progress.textContent.replace(/"/g, "");
                progress.textContent = progress.textContent.replace(/,/g, " • ")

                document.body.appendChild(number);
                document.body.appendChild(email);
                document.body.appendChild(joinDate);
                document.body.appendChild(currentPhyx);
                document.body.appendChild(name);
                document.body.appendChild(lastName);
                document.body.appendChild(lastDate);
                document.body.appendChild(progress);
                document.body.appendChild(br); 
                i++;
                }
            });
        });

I tried doing

ref.orderByChild("joinDate").on('value', function(snapshot) {
...
...
}

This doesn't work either my data looks like this :- Firebase image

What exactly does "this doesn't work" mean? Given that `joinDate` is a String, my guess is the result is ordered by month first or something? You should use a timestamp instead and format it for display. — , Nov 21 '19 at 18:46

score 1 · Accepted Answer · answered Nov 21 '19 at 22:42

Your joinDate properties hold string values in dd/MM/yyyy format. Since they are string value, they are ordered lexicographically. And in lexicographical order, for example, "01/15/2020" comes before "21/11/2019".

To allow chronological ordering you have two main options:

Store the dates as actual Date values in Firestore.
Store the dates in strings that ensure the lexicographical order it the same as the chronological order, e.g. "2019-11-21" comes before "2020-01-15".

Also see:

Firebase query by date string (for Realtime Database, but the exact same problem and solution)
How to retrieve data from firebase where the value of a date is 1 month ago from current date
How does Firestore query operation strings treat different data types?
How to order data from Firestore in Flutter, orderBy not ordering correct

Hey thank you for the answer i tried doing, `var newdate = date.split("/").reverse().join("-"); console.log("New Date is ", newdate);`. but it returns the date as `yyyy-dd-mm`. Can you please help me convert it to `yyyy-mm-dd`. — Phyxable, Nov 22 '19 at 18:02
`var parts = "01/15/2020".split("/"); result = parts[2]+"-"+parts[0]+"-"+parts[1];` — Frank van Puffelen, Nov 22 '19 at 18:09

How to sort firebase users based on date?

1 Answers1